This invention relates to a copier with variable magnification means and more particularly to a copier with which the user can set a reference position such that an image can be formed with magnification varied with respect to this reference position. In other words, a copier of the present invention allows the user, after an original document to be copied is placed on its document table, to specify a position in the direction of the scan or a position on the document with respect to which enlargement or reduction is to be effected.
Variable magnification copiers have been in use but if use is made of a copy paper sheet of the same size as the original document to make an enlarged copy with a prior art copier, a back portion (with respect to the direction of scan) of the image sticks out of the paper and is not copied. This is illustrated in FIGS. 8(A) and 8() by way of an example wherein it is desired to obtain an enlarged copy of a portion (indicated by a shaded rectangular area) of a document with its front edge at distance l from the front edge of the document as shown in FIG. 8(A). If this area of interest is sufficiently near the back edge of the document and if the desired magnification M is sufficiently large, the enlarged image of the area of interest (indicated by a large shaded rectangle) may partially stick out of the normally placed copy paper which is assumed in this example to be of the same size as the original document as shown in FIG. 8(B). This occurs because the front edge of the document is treated as the reference position for the magnification such that the front edge of the image of interest is at the distance of lM from the front edge of the copy paper sheet. With a prior art copier, therefore, it is necessary to place the original document somewhere away from the normal document position on the document table. Similarly, if a copy paper sheet of the same size as the original document is used with such a prior art copier to obtain a copy reduced in size, the image of an area of interest is formed near the front edge of the copy paper sheet. This is again because the reference position for reduction is at the front edge of the document. If it is desired to leave some space along an edge of the copy paper, for example, for the purpose of binding, the original document again must be placed somewhere away from the normal document position.